Longitudinal and Cross-Sectional Estimates of Pulmonary Function Decline in Never-Smoking Adults

Abstract

This paper describes methods for simultaneous cross-sectional and longitudinal analysis of repeated measurements obtained in cohort studies with regular examination schedules, then uses these methods to describe age-related changes in pulmonary function level among nonsmoking participants in the Six Cities Study, a longitudinal study of air pollution and respiratory health conducted between 1974 and 1983 in Watertown, Massachusetts; Kingston and Harriman, Tennessee; St. Louis, Missouri; Steubenville, Ohio; Portage, Wisconsin; and Topeka, Kansas. The subjects, initially aged 25-74, were examined on three occasions at 3-year intervals. Individual rates of loss increased more rapidly with age than predicted from the cross-sectional model. For example, for a male of height 1.75 m, the cross-sectional model predicted an increase in the annual rate of loss of FEV1 from 23.7 ml/yr at age 25 to 39.0 ml/yr at age 75, while the longitudinal model gave rates of loss increasing from 12.9 ml/yr at age 25 to 58.2 ml/yr at age 75. These results contrast with those of other studies comparing longitudinal and cross-sectional estimates of pulmonary function loss.

Longitudinal Change in FEV1 and FVC in Chronic Spinal Cord Injury

“…There was an age-related acceleration The results of this study suggest a model of pulmonary function loss after SCI in which neurologic completeness and level of injury account for a reduction in the level of FEV 1 and FVC, but do not directly influence longitudinal decline. Decline in FVC and FEV 1 in persons without SCI is known to accelerate with age, and although the effect of age cannot be directly compared with previous studies, our results indicate that effect is of similar magnitude as in able-bodied persons (23). Crosssectional studies, including our own, have described a significant age-independent association between years of injury and lower values of FEV 1 and FVC that were greatest in persons with higher and more neurologically complete SCI (4,14,15).…”

Ponto ótimo cardiorrespiratório: uma variável submáxima do teste cardiopulmonar de exercício

“…Regarding the ventilatory variables, it is known that, over the years, there is also a reduction in respiratory muscle strength 26 and some ventilatory indicators, such as forced expiratory volume in one second (FEV1) 27 and forced vital capacity (FVC ) 28 , as well as a less effective response to the increase in PaCO2 at rest 29 .…”

Longitudinal modeling of frontal cognition in APOE ε4 homozygotes, heterozygotes, and noncarriers

“…17 The acceleration of the rate of decline for each of the predetermined measures for carriers (collectively and also separately for each of the subgroups of HMZ and HTZ) was compared to those of the noncarriers using a mixed model approach for modeling cross-sectional and longitudinal data. 17,18 A quadratic model was selected to allow for comparison of the acceleration in the rate of decline between groups, as well as linear effects (velocity of decline). Modeling was carried out using SAS Proc Mixed (SAS version 9).…”